This invention is generally directed to toner and developer compositions, and more specifically, the present invention is directed to developer and toner compositions containing novel polyimide resins, and process for the preparation thereof. In embodiments, there are provided in accordance with the present invention low cost and deinkable toner compositions comprised of certain economical polyimide resins obtained, for example, by melt condensation processes, and pigment particles comprised of, for example, carbon black, magnetites, or mixtures thereof, cyan, magenta, yellow, blue, green, red, or brown components, or mixtures thereof, thereby providing for the development and generation of black and/or colored images. In embodiments, there are provided in accordance with the present invention polyimide resins I, II, or mixtures thereof of the following formulas ##STR2## wherein n represents the number of repeating segments and can be a number of from about 10 to about 100,000 and preferably from about 10 to about 50,000; and R is an alkylene, oxyalkylene or polyoxyalkylene. The toner compositions of the present invention in embodiments possess a number of advantages including excellent deinkability, possess low fixing characteristics such as from about 120.degree. C. to about 135.degree. C., excellent blocking characteristics such as from about 45.degree. C. to about 65.degree. C., excellent nonvinyl-offset properties, and low relative humidity sensitivities. The polyimides of the present invention can in embodiments be generated by the reaction of a dianhydride such as 5-(2,5-dioxotetrahydrol)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (III) or 5-(2,5-dioxotetrahydrol)-4-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (IV) available as B-4400 and B-5060, respectively, from Dai Nippon Ink Company, ##STR3## and a diamino terminated oxyalkyl or polyoxy alkyl, such as JEFFAMINES.TM. available from Texaco Chemicals as JEFFAMINE D-230.TM., D-400.TM., D-700.TM., EDR-148.TM., EDR-192.TM. and believed to be of the following formula, or aliphatic diamines like DYTEK.TM. ##STR4## wherein EDR-148 n=2;R=H
EDR-192 n=3;R=H PA1 D-230 n=2, 3; R=CH.sub.3 PA1 D-400 n=5, 6; R=CH.sub.3.
The aforementioned polyimides exhibit in embodiments a number average molecular weight of from about 2,500 grams per mole to about 100,000 grams per mole as measured by vapor phase osmometer, have a glass transition temperature of from about 45.degree. C. to about 65.degree. C., and more preferably of from about 50.degree. C. to about 65.degree. C. as measured by the Differential Scanning Calorimeter, low fixing characteristics, such as from about 125.degree. C. to about 145.degree. C., and excellent deinkability.
In another embodiment, the polyimides of the present invention can be branched or crosslinked by utilizing an alkyltriamine or oxyalkyltriamine, such as JEFFAMINE T-403.TM. available from Texaco Company, and believed to be of the formula ##STR5## wherein the summation of x, y and z is about 5.3. The amount of branching monomer utilized is of from about 0.5 to about 6 percent by weight of polyimide.
A number of toner resins are known, such as styrene acrylates, styrene methacrylates, styrene butadiene, polyesters, polyamides, and the like.
Certain polyimide resins and, more specifically, liquid crystalline polyimide resins are known such as summarized and illustrated in the Encyclopedia of Polymer Science and Engineering, 2nd Edition, Volume No. 12, published by Wiley (1985). However, such polyimide resins are aromatic and useful as high performance materials, there being no disclosure for use as toners.
Thermotropic liquid crystalline polyimides are illustrated in copending application U.S. Pat. No. 5,348,830 the disclosure of which is totally incorporated herein by reference, which discloses toner and developer compositions with thermotropic liquid crystalline polyimides. The polyimide resins of this invention differ in that, for example, they do not exhibit liquid crystalline properties, and, moreover, are of substantially lower cost such as from about 80 percent to about 500 percent less than the liquid crystalline polyimides of U.S. Pat. No. 5,348,830 as estimated, for example, from the Chemical Marketing Reporter (1993 issue). Also, the imide structures of the resins of the present invention are comprised of a cyclic six membered ring containing a tertiary alkyl amine as contrasted to the aforementioned liquid crystalline polyimides of copending application U.S. Pat. No. 5,348,830 wherein the imide structure is comprised of a five membered cyclic ring without a tertiary alkyl amine moiety.
Illustrated in the following copending applications, the disclosures of each being totally incorporated herein by reference, are:
U.S. Ser. No. 144,075 illustrates a toner composition comprised of a pigment and a crosslinked polyimide; and wherein the crosslinked polyimide can be obtained from the reaction of a peroxide with an unsaturated polyimide of the formula ##STR6## R is alkylene or oxyalkylene, and m represents the number of monomer segments present and is a number of from about 10 to about 1,000.
U.S. Pat. No. 5,348,831 illustrates a toner composition comprised of pigment, and a polyester imide resin of the formula ##STR7## wherein n represent the number of segments present and is a number of from about 10 to about 10,000; R' is alkylene; and R is independently selected from the group consisting of an oxyalkylene and polyoxyalkylene.
U.S. Ser. No. 144,918 illustrates a toner composition comprised of pigment, and polyimide of the formula ##STR8## wherein m represents the number of monomer segments present; X is ##STR9## thus X can be benzophenone, oxydiphthalic, hexafluoropropane diphenyl, diphenyl sulfone, or biphenyl; and X is attached to four imide carbonyl moieties; and R is independently selected from the group consisting of alkyl, oxyalkylene and polyoxyalkylene.
U.S. Ser. No. 221,596 illustrates a toner comprised of pigment, and a polyimide-imine resin of the formula ##STR10## wherein m, and n represent the number of monomer segments; X is independently selected from the group consisting of a tetravalent aromatic, polyarylomatic or cycloaliphatic group with from about 6 to about 20 carbon atoms and a cycloaliphatic group; R is independently selected from the group consisting of alkylene, oxyalkylene and polyoxyalkylene; and R' is independently selected from the group consisting of alkylene and arylene. The toners of the copending application U.S. Ser. No. 221,596 can be considered deinkable in embodiments in caustic aqueous conditions of from about pH of 10 to about a pH of 14, and wherein the toner resin is believed to be decomposed to oligomers. One consequence of this is that the toner can be difficult to remove during the recycling of waste xerographic copies. This difficulty manifests itself in, for example, two ways. During the caustic repulping of the waste paper, the toner is not dissolved and adheres to the paper, which is reduced to pulp, and a significant fraction of the toner specks are found to remain attached to cellulose fibers at the conclusion of this step. Also, the ink specks are found to be large when compared with those resulting from other types of printed waste, such as newsprint or lithographic printing. The size of these ink specks from conventional xerographic copy, typically 100.times.100.times.10 microns in dimensions, render them too large to separate from pulp by the most common deinking separatory techniques. This differs from the present invention in embodiments with regard to deinkability in that, for example, the developers thereof are deinked from paper at milder caustic conditions, such as from about pH of 8 to about a pH of 10 with surfactants, and wherein the toner resin is believed to be dissolved.
Further, illustrated in copending patent applications U.S. Ser. No. 200,988 is a positively charged liquid developer comprised of thermoplastic resin particles, optional pigment, a charge director, and a charge adjuvant comprised of a polymer of an alkene and unsaturated acid derivative; and wherein the acid derivative contains pendant ammonium groups, and wherein the charge adjuvant is associated with or combined with said resin and said optional pigment; and in U.S. Ser. No. 204,012 is a negatively charged liquid developer comprised of thermoplastic resin particles, optional pigment, a charge director, and an insoluble charge adjuvant comprised of a copolymer of an alkene and an unsaturated acid derivative, and wherein the acid derivative contains pendant fluoroalkyl or pendant fluoroaryl groups, and wherein the charge adjuvant is associated with or combined with said resin and said optional pigment, the disclosures of which are totally incorporated herein by reference.